The present invention relates to a coupling device for a fluid transfer line, to a fuel injector return circuit incorporating it, and to a method for fitting/removing this device around a male tubular end fitting and into/from in a female tubular end fitting that is to be coupled to this male end fitting. The invention applies in general to any couplings between such end fittings that transfer a fluid, particularly at low pressure, and notably to fuel injection line sets for motor vehicles.
In general, it is known practice for fuel injection line sets to use coupling devices involving a male tubular end fitting that is pushed in a leaktight manner into a female tubular end fitting or “canular” by means of a flexible linking member which is mounted securely on the male end fitting and which can be locked at its axially inner end into an internal circumferential groove of the female end fitting under the control of a locking member collaborating with an axially outer part of this linking member.
Mention may, for example, be made of document WO-A-2007/042344 which discloses such a device in which the linking member comprises two diametrically opposite axial arms which are formed as a single piece with the male end fitting and which lock elastically into the groove of the female end fitting by a bending force applied to them in the radial direction, that prevents them from being pulled axially outward.
One major disadvantage of these known coupling devices is that when the male end fitting is locked into the female end fitting when the linking member is not positioned in the coupling groove of the female end fitting, it is no longer subsequently possible to bring the linking member into this groove.
One other disadvantage of these known devices is that they all require two separate components (i.e. a linking member that makes the connection in the groove of the female end fitting and a locking member for locking this linking member), which means that the operation of assembling these components is not always easy and furthermore the cost of the device is relatively high notably because of the use of different materials for these components.